A standard plumbing fitting such as described in German patent document 3,519,652 filed 01 June 1985 by Luke Rainer has a mounting plate that is fixed in the Wall and to Which hot- and cold-water risers are connected. To this end an anchor plate is bolted in the wall and carries a threaded stud that projects perpendicular to the wall surface from this anchor. For mounting the fitting, same is simply screwed down onto the threaded stud and, once it is in the desired position, a counternut is screwed forward along the stud against the back of the fitting to lock it in place. Then the water connections are made to the fitting.
Such an arrangement has several disadvantages. First of all it is necessary to get at least limited access to the back of the fitting to tighten the counternut. It is also necessary to be able to rotate the entire fitting to install it, so installation in cramped surroundings is difficult or impossible. Finally, there is no way to adjust the position of the fitting subsequent to installation, as once the fitting is connected to the hot- and cold-water lines it is impossible to rotate the fitting and screw it along the stud. Finally the metal-to-metal mounting of the fitting to the stud makes for good sound transmission from the fitting to the anchor and through this anchor to the wall.